ELMA, NY - The Erie County Sheriff's Department is investigating a two-vehicle accident on Route 400 that left a pregnant woman in critical condition Tuesday night.

On Wednesday, deputies held a press conference to release additional information on the crash.

It happened around 10:20 p.m. in the northbound lanes of the 400 about one mile south of Transit Road.

Deputies were on the scene quickly and knew immediately that serious injuries were involved, said Erie County Sheriff Public Services Division Chief Scott Joslyn.

The crash is still being investigated, but deputies do know a Kevin Geary, 25, of East Aurora was driving a 2011 Dodge Ram Pickup to work when he struck a 2009 Kia Sedona from behind, which was being driven by a pregnant woman: Nadjha Davis, 23, of Buffalo. Davis was on her way home from work, Joslyn said.

Davis was found unconscious and flown to ECMC. Geary was also transported to ECMC for treatment of his injuries.

Davis is currently listed in critical condition. Officials have not said how pregnant Davis was.

The vehicles have been impounded and will be inspected to help determine the cause of the accident, Joslyn said.

Route 400 northbound was closed for most of the night due to a large debris field and the accident investigation, but reopened shortly before 10 A.M. Wednesday morning.

The Sheriff's Department is encouraging anyone who may have information on the accident to call the Sheriff's Office at 716-858-2903.